Use location and rotation 0,0,0 for all exported meshes
Im not entirely sure on what youre trying to do but I'm assuming you want to import a 3d file and move it to a specific location and rotate it?
I think your problem may be:
MeshObject = ob_for_convert.to_mesh()

What I usually use is:
block = bpy.context.selected_objects[0]

Then we can move the location and rotation:
block.location = (1,1,1)
block.rotation_euler = (0,45,0)

Some code I wrote that does what I think you want it to do (or similar):
import bpy

file_loc = 'file/dir/object.obj'
imported_object = bpy.ops.import_scene.obj(filepath=file_loc)

bpy.ops.object.duplicate()

block = bpy.context.selected_objects[0]

block.location = (1,1,1)
block.rotation_euler = (0,45,0)